The present invention relates to a semiconductor structure including a metal-insulator-metal capacitor (MIMCAP) compatible with finFET structures, and methods of manufacturing the same.
Capacitors are employed as passive components in a semiconductor chip. Capacitors are employed to decouple power supplies, to form a memory element, to form an RC delay circuit, and/or to provide various other circuit functions. Because capacitors tend to take up a significant circuit area, compact high capacitance capacitors are desirable for highly-integrated advanced semiconductor chips. At the same time, the number and complexity of additional processing steps for adding capacitors should be minimized in order to contain the total processing cost and to minimize the total processing time for semiconductor chips.
The advent of finFETs, i.e., field effect transistors formed on semiconductor fins having a height greater than the width, alters the processing steps of conventional planar field effect transistors significantly. For example, semiconductor fins are formed by patterning a top semiconductor layer of a semiconductor-on-insulator (SOI) substrate. Thus, the conventional planar capacitor that employs an upper portion of a semiconductor substrate as a lower plate cannot be formed on a substrate including finFETs.